Plant Organs and Systems

Levels of organization for plants and animals Cells Tissues Organs Organ Systems

Plant organization Plant cell (bark cell) Plant tissue (bark tissue) Plant organ (leaves, stems, roots) Plant system (work together to make, transport, and store food)

Plant Organs Leaf: function: make food, give shape, keep water inside plant cuticle Vascular bundle (xylem & phloem) epidermis palisade mesophyll spongy mesophyll lower epidermis stomata guard cell

Leaf Parts: Cuticle: waxy layer on outside surface, prevents water loss Epidermis: outer layer, protection Mesophyll: photosynthetic tissue, made up of 2 layers Stomata: openings on leaf surface for exchange of gases Guard cell: controls the size of the stomata Xylem: carries water from roots to leaves Phloem: carries food from leaves to other parts of the plant

Plant Organs Stems: functions: hold the leaves up, moves water, food, and other materials.

Plant Organs Roots: functions: take in water and other materials from soil, hold plant in soil, store extra food

Plant Organs Flowers: Non reproductive parts = petal and sepal Reproductive parts = stamen and pistil Stamen – male reproductive part contains the anther which makes the pollen containing sperm Pistil – female reproductive part contains the ovary at the bottom which holds ovule that makes the eggs

In plants, sexual reproduction takes place in the flower.

Flower Structure

Female Parts Pistil = the female structure of the flower Ovary = contains ovules where eggs are formed. Stigma = receives the pollen during fertilization. Style = area between the stigma and ovary.

Male Parts Stamen = the male reproductive structure of a flower Anther = where pollen is produced. Filament = holds up the anther Pollen = male gamete Pollen shape is different for each plant

Other Flower Structures Petals = usually colorful, leaf-like structures surrounding the male and female reproductive organs. Sepals = found below the petals and encase the rest of the flower when it is in bud and not yet opened

Plant Processes Transpiration: the evaporation of water from the stomata of leaves Absorption: uptake of water from the roots Response to stimulus: plants respond to external stimuli from a specific direction Ex: tropisms

Tropisms: “trop” = turn, change “ism” = thing Phototropism = the tendency of a plant to move towards a light source Hydrotropism = the tendency of a plant to grow with the roots reaching toward water Geotropism = the tendency of a plant to grow with the roots downward and with the leafy parts upward